PSERC EVALUATING PROTECTIVE RELAY OPERATION THROUGH TESTING

Transcription

1 EVALUATING PROTECTIVE RELAY OPERATION THROUGH TESTING Mladen Kezunovic Eugene E. Webb Professor Texas A&M University Seminar, April 6, 2004

2 Outline Why relay testing? What is the relay performance of interest? What is the existing relay test practice? How the existing practice may be enhanced? What would be the new (preferred) testing methodology and tools? What would be the benefits? Conclusions Q/A 2

3 Why Relay Testing? This varies according to specific needs: - verify that a relay product is acceptable (production)=type test - verify that relay settings are calibrated and relays are connected correctly=commissioning test - verify that a relay maintains correct calibration of settings=periodic maintenance test - verify that the performance for a given application is adequate=application test - explain relay miss operation= Troubleshooting test 3

4 Outline Why relay testing? What is the relay performance of interest? What is the existing relay test practice? How the existing practice may be enhanced? What would be the new (preferred) test methodology and tools? What would be the benefits? Conclusions Q/A 4

5 What is the relay performance of interest? Type, commissioning and periodic tests: -Correct operating characteristic (comparing to what is given in manuals) -Correct settings (comparing to what was calculated and entered) Application and troubleshooting tests: - Trip/no trip decision - If a correct trip, what is the operating time - If an incorrect trip, what was the reason 5

6 What is the relay performance of interest? Recommended statistics: - Dependability (should trip when there is a fault) - Security (should not trip when there is no fault) Recommended practices after an event (Northeast black out of August 14, 2003): - NERC Actions, February 10, Group: Data Exploration and Requirements 6

7 NERC Actions:February 10, 2004 Overview of conclusions: - Available system protection technologies were not consistently applied to optimize the ability to slow or stop an uncontrolled cascading failure of the power system Overview of recommendations: - Improve system protection to slow or limit the spread of future cascading outages 7

8 Recommendations Strategic (#5): Need to improve relay protection schemes and coordination Technical (#8): Improve system protection to slow or limit the spread of future cascading outages: a.) better application of Zone III relays b.) selective use of under-voltage load shedding c.) revision to the criteria for slowing/limiting propagation of cascading failures 8

9 Recommendation #8 #8a.: Zone III relays - Zone III relay should not operate at or below 150% of the emergency power rating of a line assuming.85% p.u. voltage and line phase angle of 30 degrees - Out of step conditions should not confuse the relay #8b.: Under-voltage load shedding -low voltage with both high and low frequencies should be considered - coordination with generator under- and overfrequency protection and controls #8c.: propose revisions to the planning criteria 9

10 Group for Data Exploration and Requirements NERC Planning Standard specifies Testing and maintenance requirements: Responsibility for maintenance and/or testing Relay type,settings, targets and causes of trips were requested Group did not make any reference to the relay test data being available and used for blackout investigation Recommendation was to standardize data collection but NOT to perform any relay tests 10

11 Outline Why relay testing? What is the relay performance of interest? What is the existing relay test practice? How the existing practice may be enhanced? What would be the new (preferred) test methodology and tools? What would be the benefits? Conclusions Q/A 11

12 What is the existing relay test practice? Phasor testing procedure: - Uses traditional test sets (Doble, Megger, Omicron, Manta, etc) - Sets a fixed voltage and ramps current from zero until the relay operates - Repeats such a test for several operating points - Performs tests in the field or on a relay manufacturing floor 12

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14 Outline Why relay testing? What is the relay performance of interest? What is the existing relay test practice? How the existing practice may be enhanced? What would be the new (preferred) testing methodology and tools? What would be the benefits? Conclusions Q/A 14

15 How the existing practice may be enhanced? Phasor testing: - More MEANINGFUL tests - BETTER testing TOOLS Transient testing: - use it to evaluation performance of relay products BEFORE PURCHASE - Use it to evaluate relay performance IN- SERVICE 15

16 Comprehensive list of Test Cases (Phasor Testing) 16

17 Artificial Test Waveforms 17

18 One-terminal system representation 18

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23 Test result summary Different Cases Different fault types for the same relay Different relays Different load currents Different source impedance ratio 23

24 ABC fault x: Case I o: Case II *: Case III 24

25 Test result summary Different Cases Different fault types for the same relay Different relays Different load currents Different source impedance ratio 25

26 A-G fault (Relay A) x: Case I o: Case II *: Case III 26

27 BC fault (Relay A) x: Case I o: Case II *: Case III 27

28 BC-G fault (Relay A) x: Case I o: Case II *: Case III 28

29 Test result summary Different Cases Different fault types for the same relay Different relays Different load currents Different source impedance ratio 29

30 BC fault (Relay B) x: Case I o: Case II *: Case III 30

31 BC fault (Relay C) x: Case I o: Case II *: Case III 31

32 : Three-phase fault theoretical characteristics : Single-line-to-ground fault theoretical characteristics : Line-to-line fault theoretical characteristics x : Three-phase fault test results o : Single-line-to-ground fault test results * : Line-to-line fault test results Comparison of theoretical analysis and test for Relay B 32

33 Test result summary Different Cases Different fault types for the same relay Different relays Different load currents Different source impedance ratio 33

34 Relay A, BC fault x: I = 5-30 A; o: I = 0 A; *: I = A 34

35 Test result summary Different Cases Different fault types for the same relay Different relays Different load currents Different source impedance ratio 35

36 Relay C, BC fault x: SIR = 1.24 o: SIR =

37 Two-terminal system representation 37

38 How the existing practice may be enhanced? Phasor testing: - More MEANINGFUL tests - BETTER testing TOOLS Transient testing: - use it to evaluate performance of relay products BEFORE PURCHASE - Use it to evaluate relay performance IN- SERVICE 38

39 Transient Testing Case I: Creating test waveforms through modeling and simulation Case II: Creating test test waveforms through replaying the field-recorded data Evaluating - Application: Correct/incorrect operation for a selected application - Statistical properties: trip/no trip decision and trip time for number of applications 39

40 Example: Application tests 40

41 Example: Application tests Sequence of events: fault on the STP-SKY line Relay #2 trips first and sends the carrier signal Relay #1 trips after receiving the carrier signal the auto-reclosure is not successful and both relays trip 41

42 Example: Application Tests Sequence of events: fault on the STP-SKY line Relay #2 trips first and sends the carrier signal Relay #1 trips after receiving the carrier signal the auto-reclosure is not successful and both relays trip 42

43 Example: Statistical Tests Trip/no trip decision: - Repetitive tests to assess dependability/security Trip time: - Repetitive tests to assess application features (time coordination, etc.) 43

44 Example: Trip/No-Trip Evaluation 44

45 Example: Trip time 45

46 Example: Trip time (comparative) 46

47 Outline Why relay testing? What is the relay performance of interest? What is the existing relay test practice? How the existing practice may be enhanced? What would be the new (preferred) test methodology and tools? What would be the benefits? Conclusions Q/A 47

48 Typical Hardware Options Simulation Computer I/O Subsystem Digital Analog Digital Data Acquisition RELAY 48

49 Typical Hardware Tools Relay Commercial Amplifiers Commercial Amplifiers Commercial D/A Boards PC bus Commercial Test Sets Commercial I/O Boards Std. comm. Interface Custom I/O Hardware Custom Interface PC Simulation Computer (PC) 49

50 Hardware Options AVO s PULSAR Test Sets V-Amplifier V-Amplifier V-Amplifier TLI s I/O Box (D/A conversion) V-Amplifier V-Amplifier V-Amplifier TLI s I/O Box (D/A conversion) C-Amplifier C-Amplifier C-Amplifier C-Amplifier C-Amplifier C-Amplifier TLI s I/O Box + High Power Amplifiers PC-based Open-Loop Simulator 50

51 Typical Software Tools DFR Transient Simulation Program (EMTP, ATP, etc.) DFR Files Comtrade Files ATP/ EMTP Files Other Waveform Files Data Generating Routine File Format Conversions Processing Relay Response GUI Processing Processing Processing FFT FFT Spectrum Editing Cut, Paste Waveform Replaying Engine Comm. Program To I/O Hardware 51

52 Software Options ATPDraw Base Model ATPDraw Input File Base Model ATP Input File Test Cases ATP Input Files BGEN ATP Test Cases ATP Output Files Batch of Tests Relay Assistant File (COMTRADE waveforms) Relay Assistant Simulator Hardware Reports Text Files Connected to Relay 52

53 Outline Why relay testing? What is the relay performance of interest? What is the existing relay test practice? How the existing practice may be enhanced? What would be the new (preferred) testing methodology and tools? What would be the benefits? Conclusions Q/A 53

54 What would be the benefits? Purchase the best products for a given application Make sure the installed equipment is operating correctly Analyze any problems efficiently and in great detail Demonstrate to a regulator a reliable (selective) performance 54

55 Outline Why relay testing? What is the relay performance of interest? What is the existing relay test practice? How the existing practice may be enhanced? What would be the new (preferred) testing methodology and tools? What would be the benefits? Conclusions Q/A 55

56 Conclusions Existing test practice serves a limited purpose The purpose IS to check Setting CALIBRATION and NOT to evaluate relay application performance Relay PERFORMANCE needs to be evaluated to assure the BEST decision regarding: - investment - application practices - relay performance under critical conditions 56

57 References M. Kezunovic, Y.Q. Xia, Y. Guo, C.W. Fromen, D.R. Sevcik, "Distance Relay Application Testing Using a Digital Simulator", IEEE Transactions on Power Delivery, Vol.12, No.1,January 1997, pp M. Kezunovic, Y.Q. Xia, Y. Guo, C.W. Fromen, D.R. Sevcik, "An Advanced Method for Testing of Distance Relay Operating Characteristic", IEEE Transactions on Power Delivery, Vol.11, No.1, pp , January W. Fromen, D.R. Sevcik, M. Kezunović, Trouble Shooting of Generator Differential Relay Operation Using Digital Simulators, 53 rd Annual Conference for Protective Relay Engineers, College Station, April

58 Outline Why relay testing? What is the relay performance of interest? What is the existing relay test practice? How the existing practice may be enhanced? What would be the new (proffered) test methodology and tools? What would be the benefits? Conclusions Q/A 58

59 The End Q/A 59

60 Appendix Simulator types Simulator architecture (generic) Simulator software Simulator hardware Vendor information: 60

61 Simulator Types Open-loop Simulator (Playback Digital Simulator): the response of an apparatus under test does not affect the simulation Close-loop Simulator: the response of an apparatus under test is fed back into the simulator and possibly affects the simulation (trip signals relayed to the models of circuit breakers, for example) 61

62 Simulator Types Real-time Simulator: the calculations for the output signals require less time than the sampling period. Thus, the computations can be done on-the-fly, i.e. in real-time Playback Simulator: the calculations for the output signals require more time than the sampling period. Thus, the computations must be done off-line, the results stored and next just played-back 62

63 Generic Architecture U S E R I N T E R F A C E EMTP Software IT Models Relay Models I/O Interface Power Amplifiers Protective Relay Simulation Environment Digital Simulator 63

64 Generic Architecture EMTP Software U S E R I N T E R F A C E EMTP Software IT Models Relay Models I/O Interface Power Amplifiers Protective Relay Simulation Environment Digital Simulator 64

65 Generic Architecture EMTP Software EMTP (EPRI/DCG) ATP (US/Canada/European) MORGAT, ARENE (EdF) NETOMAC (Siemens / TU Berlin) MicroTran EMTDC (Manitoba Hydro / RTDS Inc.) RTS (TAMU / TLI Inc.) 65

66 Generic Architecture IT Models U S E R I N T E R F A C E EMTP Software IT Models Relay Models I/O Interface Power Amplifiers Protective Relay Simulation Environment Digital Simulator 66

67 Generic Architecture IT Models Instrument Transformers (ITs) have to be modeled for accurate relay testing: ITs can be simulated by the EMTP software of a simulator ITs can be simulated by the specialized software for enhancing the simulation power of the entire simulator 67

68 Generic Architecture IT Models - Example: CCVT PCA-5 CCVT 68

69 Generic Architecture Relay Models U S E R I N T E R F A C E EMTP Software IT Models Relay Models I/O Interface Power Amplifiers Protective Relay Simulation Environment Digital Simulator 69

70 Generic Architecture Relay Models A given relay can be tested using simulation if its software model is available Also, to test a given physical relay in situations involving relay interaction, other relays may need to be simulated by the simulator 70

71 Generic Architecture User Interface U S E R I N T E R F A C E EMTP Software IT Models Relay Models I/O Interface Power Amplifiers Protective Relay Simulation Environment Digital Simulator 71

72 Generic Architecture User Interface Means for Network Modeling Tools for Signal Editing and Viewing Test Set-up and Selection of Test Files Automated Batch Processing of Tests Test Result Reporting and Analyzing 72

73 Generic Architecture I/O Interface U S E R I N T E R F A C E EMTP Software IT Models Relay Models I/O Interface Power Amplifiers Protective Relay Simulation Environment Digital Simulator 73

74 Generic Architecture I/O Interface D/A Conversion Digital I/O A/D Conversion 74

75 Generic Architecture Signal Reconstruction Requirements WAVEFORM RECONSTRUCTION SUBSYSTEM Simulation Computer I/O Subsystem Power Amplifiers Device Under Test Waveform Reconstruction Subsystem Requirements I/O Subsystem Requirements Power Amplifiers Subsystem Requirements Voltage Amplifiers Requirements Current Amplifiers Requirements 75

76 Generic Architecture Typical I/O Subsystem Specifications 76

77 Generic Architecture Power Amplifiers U S E R I N T E R F A C E EMTP Software IT Models Relay Models I/O Interface Power Amplifiers Protective Relay Simulation Environment Digital Simulator 77

78 Generic Architecture Typical Power Amplifiers Specifications 78

79 Generic Architecture Relay Requirements U S E R I N T E R F A C E EMTP Software IT Models Relay Models I/O Interface Power Amplifiers Protective Relay Simulation Environment Digital Simulator 79

80 Generic Architecture Relay Requirements 80

81 Further reading Simulator types Simulator architecture Simulator hardware/software Relay modeling Instrument transformer modeling User Interface Web site with references that can be downloaded: 81

82 Simulator types M. Kezunović, J. Domaszewicz, V. Skendžić, M. Aganagić, J.K. Bladow, S.M. McKenna, D.M. Hamai, Design, Implementation and Validation of a Real-Time Digital Simulator for Protection Relay Testing, IEEE Transactions on Power Delivery, Vol. 11, No. 1, pp , January M. Kezunović, S.M. McKenna, Real-Time Digital Simulator for Protective Relay Testing, IEEE Computer Applications in Power, Vol. 7, No. 3, pp , July M. Kezunović, Modular Simulators Match Cost and Performance Criteria, IEEE Computer Applications in Power, pp , April M. Kezunović, A. Abur, Lj. Kojović, V. Skendžić, H. Singh, DYNA- TEST Simulator for Relay Testing, Part I: Design Characteristics, IEEE Transactions on Power Delivery, Vol. 6, No. 4, pp , October M. Kezunović, A. Abur, Lj. Kojović, V. Skendžić, H. Singh, DYNA- TEST Simulator for Relay Testing, Part II: Performance Evaluation, IEEE Transactions on Power Delivery, Vol. 7, No. 3, pp , July

83 Simulator Architecture M. Kezunović, Z. Galijasević, PC Based Dynamic Relay Test Bench, Int l. Conference on Modern Trends in the Protection Schemes of Electric Power Apparatus and Systems, New Delhi, India, October M. Kezunović, C.W. Fromen, D.R. Sevcik, S.M. McKenna, B.A. Pickett, N. Izquierdo, Advanced Testing Methods for Protective Relays Using New Digital Simulator Designs, 1996 CIGRÉ Session, Paris, France, August S.M. McKenna, M. Kezunović, D. Hamai, Z. Galijasević, The Choice of a Simulation Time Step in the Real-Time Simulator Applications, First International Conference on Digital Power System Simulators (ICDS '95), College Station, Texas, April 1995 M. Kezunović, A. Gopalakrishnan, J. Domaszewicz, Q. Chen, F. Ji, X. Qi, I. Rikalo, C.W. Fromen, D.R. Sevcik, S.M. McKenna, M. Hammam, Design Characteristics of an Advanced Two-Terminal Digital Simulator for Relay Testing, First International Conference on Digital Power System Simulators (ICDS '95), College Station, April

84 Simulator Hardware/software M. Kezunović, B.A. Pickett, M.G. Adamiak, G.E. Alexander, K.R. Carr, G. Chirco, J. Esztergalyos, M. Jerosolimski, W.C. Kotheimer, R. Marttila, J.L. McElray, S.M. McKenna, P.G. McLaren, R.J. Murphy, J. Nordstrom, R. Ryan, V. Skendzic, S.I. Thompson, D.A. Tziouvaras F.M. Phillips, T. Sakaguchi, R.B. Sollero, Digital Simulator Performance Requirements for Relay Testing, IEEE Transactions on Power Delivery, Vol. 13, No. 1, pp , January M. Kezunović, D. Tziouvaras, B.A. Pickett, P.G. McLaren, Digital Simulator Activity within IEEE Power Systems Relaying Committee, First International Conference on Digital Power System Simulators (ICDS '95), College Station, April 1995 N. Izquierdo Jr., M. Kezunović, Z. Galijasević, F. Ji, A. Gopalakrishnan, J. Domaszewicz, Digital Simulator Design for Real-Time and Open-Loop Applications, First International Conference on Digital Power System Simulators (ICDS '95), College Station, Texas, April

85 Relay Modeling P.G. McLaren, C. Henville, V. Skendzic, A. Girgis, M. Sachdev, G. Benmouyal, K. Mustaphi, M. Kezunović, Lj. Kojovic, M. Meisinger, C. Simon, T. Sidhu, R. Marttila, D. Tziouvaras, Software Models for Relays, IEEE Transactions on Power Delivery, Vol. 16, No.2, pp , April M. Kezunović, User Friendly, Open System Software for Teaching Protective Relaying Application and Design Concepts, IEEE Transactions on Power Systems, Vol. 18, No. 3, August M. Kezunović, Y. Guo, Modeling and Simulation of the Power Transformer Faults and Related Protective Relay Behavior, IEEE Transactions On Power Delivery, Vol. 15, No. 1, pp , January M. Kezunović, B. Kasztenny, R. Martinez-Lagunes, N. Suphasan, New Software Tools for Power System Relaying Utilizing Modeling and Simulation, ISCA 14 th Int l. Conference on Computers and Their Applications, Cancun, Mexico, April

86 Instrument Transformer modeling D. Tziouvaras, P. McLaren, C. Alexander, D. Dawson, J. Esztergalyos, C. Fromen, M. Glinkowski, I. Hasenwinkle, M. Kezunović, L. Kojović, B. Kotheimer, R. Ruffel, J. Nordstrom, S. Zochol, Mathematical Models for Current, Voltage and Coupling Capacitor Voltage Transformers, IEEE Transactions on Power Delivery, Vol. 15, No. 1, pp , January M. Kezunović, Lj.Kojović, V. Skendžić, C.W. Fromen, D.R. Sevcik, S.L. Nilsson, Digital Models of Coupling Capacitor Voltage Transformers for Protective Relay Transient Studies, IEEE Transactions on Power Delivery, Vol. 7, No. 4, pp , October M. Kezunović, C. Fromen, F. Phillips, Lj. Kojović, A. Abur, D. Sevcik, Experimental Evaluation of EMTP Based Current Transformer Models for Protective Relay Transient Study, IEEE Transactions on Power Delivery, Vol. 9, No. 1, pp , January

87 User Interface M Kezunović, T. Popović, D. Sevcik, M. DoCarmo, Transient Testing of Protection Relays: Results, Methodology and Tools, International Conference on Power System Transients IPST 2003, New Orleans, September 2003 M.Kezunović, T. Popović, Assessing Application Features of Protective Relays and Systems Through Automated Testing Using Transients, IEEE/PES T&D 2002 Asia Pacific Conference, Yokohama, Japan, October M. Kezunović, F. Ji, S.M. McKenna, D.Hamai, Graphical User Interface for a Digital Real-Time Simulator, First International Conference on Digital Power System Simulators (ICDS '95), College Station, Texas, April B. Kasztenny, M. Kezunović, J. Galijasević, D. Williams, A New ATP Add-On for Modeling Internal Faults in Power Transformers, American Power Conference, Chicago, April